Mon, 07 Jul 2008 16:49:25 BST CiteULike: vrich Sorensen http://www.citeulike.org/user/vrich/author/Sorensen CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/vrich/article/2776714 <i>Proceedings of the National Academy of Sciences, Vol. 103, No. 10. (7 March 2006), pp. 3846-3851.</i><br /><br />Studies of deeply buried, sedimentary microbial communities and associated biogeochemical processes during Ocean Drilling Program Leg 201 showed elevated prokaryotic cell numbers in sediment layers where methane is consumed anaerobically at the expense of sulfate. Here, we show that extractable archaeal rRNA, selecting only for active community members in these ecosystems, is dominated by sequences of uncultivated Archaea affiliated with the Marine Benthic Group B and the Miscellaneous Crenarchaeotal Group, whereas known methanotrophic Archaea are not detectable. Carbon flow reconstructions based on stable isotopic compositions of whole archaeal cells, intact archaeal membrane lipids, and other sedimentary carbon pools indicate that these Archaea assimilate sedimentary organic compounds other than methane even though methanotrophy accounts for a major fraction of carbon cycled in these ecosystems. Oxidation of methane by members of Marine Benthic Group B and the Miscellaneous Crenarchaeotal Group without assimilation of methane-carbon provides a plausible explanation. Maintenance energies of these subsurface communities appear to be orders of magnitude lower than minimum values known from laboratory observations, and ecosystem-level carbon budgets suggest that community turnover times are on the order of 100-2,000 years. Our study provides clues about the metabolic functionality of two cosmopolitan groups of uncultured Archaea. 10.1073/pnas.0600035103 Heterotrophic Archaea dominate sedimentary subsurface ecosystems off Peru Jennifer Biddle Julius Lipp Mark Lever Karen Lloyd Ketil Sorensen Rika Anderson Helen Fredricks Marcus Elvert Timothy Kelly Daniel Schrag Mitchell Sogin Jean Brenchley Andreas Teske Christopher House Kai-Uwe Hinrichs doi:10.1073/pnas.0600035103 Proceedings of the National Academy of Sciences, Vol. 103, No. 10. (7 March 2006), pp. 3846-3851. 2008-05-09T21:43:30-00:00 2006 Proceedings of the National Academy of Sciences 103 10 3846 3851 16srrna archaea fish lipids http://www.citeulike.org/user/vrich/article/2689375 <i>ISME J, Vol. 2, No. 1. (November 2007), pp. 3-18.</i> Uncultured archaea in deep marine subsurface sediments: have we caught them all? Andreas Teske Ketil Sorensen doi:10.1038/ismej.2007.90 ISME J, Vol. 2, No. 1. (November 2007), pp. 3-18. 2008-04-18T19:56:37-00:00 2007 ISME J 2 1 3 18 International Society for Microbial Ecology archaea pcr_bias